I understand that the PCM turns down oil pressure in the transmission on shifts, to soften the shifts, by varying duty cycle on the pressure control solenoid. Is this correct? I have reason to want to hold full pressure when the PCM commands a shift. Will holding the pressure control line low, 100% duty cycle, work to keep full pressure at all times? Is there any danger in doing this?
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2010 Ram 3500 Cummins, AT, 4x4, CC, LB, Line-X, B&W Turn Over Ball, RBW Lil Rocker modified to fit B&W, Milemarker hyd. winch. Elkhorn 9VS slide-in, Nomad 24 ft. fifth/w slide, Century topper, old classic Sooner 18' 4 horse stock trailer. StarFlyte by DynaMax 6.8 V10.
Formerly: 97 F-250 SC LB PSD. 4x4, With lots of Goodies. Twas a good truck. If you don't care where you are, you ain't lost.
Larry
If you go into limp mode, the transmission will shift at full pressure. 1-2 shift is especially harsh and is probably not good for the tranny shifting that hard. If you want to feel what it's like, try unplugging the ICP connector and take it for a spin. Should go into limp mode with ICP unplugged.
It doesn't feel every good. Mine has been running in limp mode on and off since i can't remember. I'm about to find out what a 6k generator is going to do to it tomm. Hopefully i won't blow too much up, but if i do, at least it'll look cool i hope.
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96' F350 4X4. E4OD tranny running Amsoil synthetic, 1 big tranny cooler and tricumulator springs and accumulator valve. Autometer guages, homemade intake, TS 6 position Chip (tuning by Diesel Innovations , Factory AIC, A/C mod, MBRP 4" Exaust, BDP Stage I injectors, Brakesmart trailer brake controller, T/C lockup switch
Soon to be installed: Innercooler (sittin at the shop), Big Oil, Built Tranny, Coolant Filter, HX hose, and some others. 350k miles.
It doesn't turn down the pressure for a shift, it controls the pressure to make a shift as the engineer designed it. If you watch the pressure during a shift it goes up and down very quickly.
I want to lock the tranny in 3rd for running on a dyno. If I manually force a lock in 3rd and the PCM attempts to do a 3-2 downshift or 2-3 upshift I don't want the glitch in pressure. I think I have a circuit that will do this. I will not be changing gears when I hold the pressure high. I want to be able to see torque curves below 2000 RPM and without a custom dyno program in my chip I can't do that without a 3-2 downshift occurring. I am very interested in what is going on at other RPMs beside peak torque and power. I hope to try the circuit on a new load dyno this Saturday. It is supposed to be much better than a Mustang. The owner says it will allow reaching full boost. I have never been impressed with the Dyno Jets.
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2010 Ram 3500 Cummins, AT, 4x4, CC, LB, Line-X, B&W Turn Over Ball, RBW Lil Rocker modified to fit B&W, Milemarker hyd. winch. Elkhorn 9VS slide-in, Nomad 24 ft. fifth/w slide, Century topper, old classic Sooner 18' 4 horse stock trailer. StarFlyte by DynaMax 6.8 V10.
Formerly: 97 F-250 SC LB PSD. 4x4, With lots of Goodies. Twas a good truck. If you don't care where you are, you ain't lost.
Larry
from my experience with a manual lockup the tranny will stay in 3rd longer with it locked, if it does downshift then it will be hard but not that bad. however it is not a good thing to use often as I did blow a TC lockup piston thsi way.
__________________ Sold to JCart , 1997 F250 FireTruck Red,CC SB,auto( Presicion TC, HD-2Tugger),5" exhaust, Swamp 140cc injectors, TWildman 4-pos chip,open air cleaner, I/C w Banks intake, ,AIC,dual electric fans,Sky mfg RSK w/ D60w/ARB locker,she's well taken care of now pictures
2004 Dodge 3500 twin turbo 525hp rocket
Basically I don't want a shift to occur once 3rd has been reached on the dyno. I want to drop back to 1500 or lower, in 3rd, and then bring it back up under full power. The TC will be locked once 3rd is reached and will remain locked. I am confident I can do this but don't want the stress on clutches and TC caused by the PCM thinking its shifting and glitching the pressure. The pressure glitches are there to reduce strain on the tranny as well as the driver but shouldn't be needed if no shift occurs even though the PCM thinks one is happening.
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2010 Ram 3500 Cummins, AT, 4x4, CC, LB, Line-X, B&W Turn Over Ball, RBW Lil Rocker modified to fit B&W, Milemarker hyd. winch. Elkhorn 9VS slide-in, Nomad 24 ft. fifth/w slide, Century topper, old classic Sooner 18' 4 horse stock trailer. StarFlyte by DynaMax 6.8 V10.
Formerly: 97 F-250 SC LB PSD. 4x4, With lots of Goodies. Twas a good truck. If you don't care where you are, you ain't lost.
Larry
why would the PCM think it si shifting?, it is either in 3rd or it will shift to second, TC lock or not, you will not be able to get it in 3rd at 1500 and floor it. Unless you get a snap-on unit that contols teh tranny and lets you manually shift the tranny and hold gears.
__________________ Sold to JCart , 1997 F250 FireTruck Red,CC SB,auto( Presicion TC, HD-2Tugger),5" exhaust, Swamp 140cc injectors, TWildman 4-pos chip,open air cleaner, I/C w Banks intake, ,AIC,dual electric fans,Sky mfg RSK w/ D60w/ARB locker,she's well taken care of now pictures
2004 Dodge 3500 twin turbo 525hp rocket
I have a trans tester at work, basicly it plugs into the unit to give you complete manual control of all the functions. It however will not control epc, it runs on a default of max duty cycle, which is what you want anyway. Its fun to put it on a tarus and go for a tire chirping test drive.
but don't they just break if you do that Jon, the Tarus I mean.
__________________ Sold to JCart , 1997 F250 FireTruck Red,CC SB,auto( Presicion TC, HD-2Tugger),5" exhaust, Swamp 140cc injectors, TWildman 4-pos chip,open air cleaner, I/C w Banks intake, ,AIC,dual electric fans,Sky mfg RSK w/ D60w/ARB locker,she's well taken care of now pictures
2004 Dodge 3500 twin turbo 525hp rocket
What I am building does exactly what the trans tester does for one specific condition. That being holding third with full pressure and TC locked all the time I command it to. I've got it built and hope to get it installed while waiting for my turn at the dyno tomorrow. If it works as planned it will allow me to start from idle and go all the way to limiter in third. I don't intend to operate it this way because of the strain on the tranny but will bring it up in normal fashion and then switch to the third only mode.
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2010 Ram 3500 Cummins, AT, 4x4, CC, LB, Line-X, B&W Turn Over Ball, RBW Lil Rocker modified to fit B&W, Milemarker hyd. winch. Elkhorn 9VS slide-in, Nomad 24 ft. fifth/w slide, Century topper, old classic Sooner 18' 4 horse stock trailer. StarFlyte by DynaMax 6.8 V10.
Formerly: 97 F-250 SC LB PSD. 4x4, With lots of Goodies. Twas a good truck. If you don't care where you are, you ain't lost.
Larry
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